feat(dashboards): Add flag for dashboards widget unfurl

[DominikB2014]

Register the organizations:dashboards-widget-unfurl feature flag to gate unfurling of dashboard widgets in Slack.

The flag is registered with api_expose=False and default=False so backend can gate widget unfurl behavior consistently while rollout is controlled via FlagPole.

Refs DAIN-1560

[linear-code]

DAIN-1560 Create flag for dashboards widget unfurl

[github-actions]

Backend Test Failures

Failures on e02877d in this run:

tests/sentry/api/serializers/test_organization.py::OrganizationSummarySerializerTest::test_simple — log

[gw1] linux -- Python 3.13.1 /home/runner/work/sentry/sentry/.venv/bin/python3
tests/sentry/api/serializers/test_organization.py:65: in test_simple
    assert result["features"] == [
E   AssertionError: assert ['advanced-se...ds-edit', ...] == ['advanced-se...ds-edit', ...]
E     
E     At index 6 diff: 'dashboards-widget-unfurl' != 'data-forwarding'
E     Left contains one more item: 'uptime'
E     
E     Full diff:
E       [
E           'advanced-search',
E           'change-alerts',
E           'crash-rate-alerts',
E           'custom-symbol-sources',
E           'dashboards-basic',
E           'dashboards-edit',
E     +     'dashboards-widget-unfurl',
E           'data-forwarding',
E           'discover-basic',
E           'discover-query',
E           'event-attachments',
E           'insight-modules',
E           'integrations-alert-rule',
E           'integrations-chat-unfurl',
E           'integrations-codeowners',
E           'integrations-deployment',
E           'integrations-enterprise-alert-rule',
E           'integrations-enterprise-incident-management',
E           'integrations-event-hooks',
E           'integrations-incident-management',
E           'integrations-issue-basic',
E           'integrations-issue-sync',
E           'integrations-scm-multi-org',
E           'integrations-stacktrace-link',
E           'integrations-ticket-rules',
E           'integrations-vercel',
E           'invite-members',
E           'open-membership',
E           'relay',
E           'session-replay-ui',
E           'shared-issues',
E           'sso-basic',
E           'sso-saml2',
E           'symbol-sources',
E           'team-insights',
E           'team-roles',
E           'uptime',
E       ]

[github-actions]

Backend Test Failures

Failures on ee95be9 in this run:

tests/sentry/api/serializers/test_organization.py::OrganizationSummarySerializerTest::test_simple — log

[gw0] linux -- Python 3.13.1 /home/runner/work/sentry/sentry/.venv/bin/python3
tests/sentry/api/serializers/test_organization.py:65: in test_simple
    assert result["features"] == [
E   AssertionError: assert ['advanced-se...ds-edit', ...] == ['advanced-se...ds-edit', ...]
E     
E     At index 6 diff: 'dashboards-widget-unfurl' != 'data-forwarding'
E     Left contains one more item: 'uptime'
E     
E     Full diff:
E       [
E           'advanced-search',
E           'change-alerts',
E           'crash-rate-alerts',
E           'custom-symbol-sources',
E           'dashboards-basic',
E           'dashboards-edit',
E     +     'dashboards-widget-unfurl',
E           'data-forwarding',
E           'discover-basic',
E           'discover-query',
E           'event-attachments',
E           'insight-modules',
E           'integrations-alert-rule',
E           'integrations-chat-unfurl',
E           'integrations-codeowners',
E           'integrations-deployment',
E           'integrations-enterprise-alert-rule',
E           'integrations-enterprise-incident-management',
E           'integrations-event-hooks',
E           'integrations-incident-management',
E           'integrations-issue-basic',
E           'integrations-issue-sync',
E           'integrations-scm-multi-org',
E           'integrations-stacktrace-link',
E           'integrations-ticket-rules',
E           'integrations-vercel',
E           'invite-members',
E           'open-membership',
E           'relay',
E           'session-replay-ui',
E           'shared-issues',
E           'sso-basic',
E           'sso-saml2',
E           'symbol-sources',
E           'team-insights',
E           'team-roles',
E           'uptime',
E       ]

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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